Adsorption Characteristics of Carbon Dioxide Gas on a Solid Acid Derivative of β-Cyclodextrin

A solid acid derivative of β-cyclodextrin was synthesized as an adsorbent for CO2 capture. The adsorption characteristics, such as adsorption capacity, selectivity, and uptake rate, under different temperatures and gas pressures were analyzed. The results from scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller (BET) sorption, Fourier transform infrared spectroscopy, andthermogravimetric analysis indicated that the dehydration and grafting of sulfonic groups changed the structure of β-cyclodextrin aggregates into a relatively homogeneous porous structure with a concave–convex surface. Meanwhile, the specific BET surface area and pore volume of the solid acid derivative were increased by 40 and 37 times compared to β-cyclodextrin aggregates. Thereby, the performance of the solid acid derivative of β-cyclodextrin toward CO2 sorption was significantly enhanced, in which CO2 adsorption capacity at 3.5 bar was increased to 1.78 mmol/g and the selectivity of CO2 over N2, O...